The construction of Ontario roads and highways have become more environmentally friendly

As you drive to work, prepare for that road trip with your friends, or pack the car for the cottage, your most pressing thought might not be on how environmentally friendly Ontario roads and highways have become over the past 10 years.

In previous articles, I have mentioned how the road building and asphalt production industry has implemented different methods to help lower greenhouse gas emissions. Some of these approaches include using recycled asphalt pavement (RAP) and implementing strict environmental practices at asphalt producing plants as part of our Trillium Awards program. In this piece, I will talk about the environmental benefits of warm mix asphalt (WMA), one of the re-emerging trends in the construction industry right now.

WMA is a different process for mixing, hauling, placing and compaction of asphalt mixtures. It is a greener process that has less impact on the environment with reduced hydrocarbon emissions and greenhouse gases. WMA is produced and mixed at temperatures not exceeding 150 °C. Latest Ontario specifications for WMA recommends a maximum allowable production temperature of 135 °C.

One of the major environmental benefits of using WMA is lower temperature applications can reduce the amount of fuel-burning energy it takes to mix asphalt at a plant. Additionally, the asphalt can be heated much more quickly at lower temperatures during the production process, which inevitably results in fewer carbon emissions being released into the ozone by approximately 30 to 35 per cent.

WMA cools at a lower rate, so the paving season is extended, allowing road repairs and construction projects to finish earlier. This benefit helps save time and money on labour and equipment as workers and tools are needed for a shorter span of time, and projects can be finished more quickly. Hence, reducing the impact on traffic, and causing fewer interruptions to roadways and highways.

For workers who deal with road-building construction sites, WMA is a much safer and healthier option. At the production plant and on-site, there are fewer fumes and smoke to inhale, minimizing lung and respiratory issues.

Since it also has fewer emissions, WMA can be used for paving even on days with poor air quality. This benefit helps minimize construction delays and keeps projects on track for completion.

WMA has been used in Europe for decades. This technology is not new to Ontario with use on provincial highways dating back as far as 2006 and many municipal trials during the last 10 years. It is quickly becoming a mainstay in construction and paving due to its versatility, lessened impact on the environment and its performance characteristics.

The overall consensus is that WMA pavements are the most environmentally sustainable option; especially due to the potential for mix optimization incorporating RAP and other repurposed paving materials.

To find out more about WMA, please visit onasphalt.com.

Bryan Hocking is the CEO of the Ontario Road Builders’ Association (ORBA). To learn more, visit orba.org or follow us on LinkedIn or Twitter.

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